Sound-absorbing material and method of making same.



COATlNG OR PLASHC. mum'lwi .I. COMERMA.

SOUND ABSORBING MATERIAL AND METHOD OF MAKING SAME.

APPLICATION mm NOV. 10. m5.

1 ,230,381 Patented June 19, 1917.

WITNESSES INVENTOR COMPOSITIONS,

COATING OR PLASTIC.

UNITED STATES PATENT OFFICE.

JOHN COMERMA, OF NEW YORK, N. Y., ASSIGNOR, BY MESNE ASSIGNMENTS, TO JOHN CABBA, OF NEW YORK, N. Y.

Specification 01' Letters Patent.

Patented June 19, 1917.

Application filed November 10, 1915. Serial N 0. 60,723.

To all whom it ma concern:

Be it known 1; at I, JOHN COMERMA, a subject of the King of Spain, and resident of the borough of Manhattan, city, county, and State of New York, have invented certain new and useful Improvements in Sound- Absorbing Material and Methods of Making Same, of which the following is a specification.

My invention relates to sound absorbing materials and has for its object to provide a material which is particularly adapted for use in forming the interior exposed surfaces of walls and ceilings of rooms, auditoriums and the like and which when so used serves to correct certain types of acoustical difliculties by preventing excessive reverberation and echo and injurious focusing of sound.

My invention further contemplates the provision of a simple and efiicient method whereby my improved material may be made.

My improvement will be fully described hereinafter and the features of novelty will be pointed out inthe appended claims.

Reference is to be had to the accompanying drawings which illustrate, diagrammatically, examples of use of my improvement and in which Figures 1 and 2 are sectional views of arches including my material; Fig. 3 is a perspective view of a unit, such as a tile or brick, including my material and Fig. 4 is a sectional view illustrating my improved material in the form of a molding.

In its preferred form my improved material comprises a mass of granules of cork which are each coated with a binding sullstance of an n suc as cement, p aster,

lue or the like and are in irregular contact ifli each other and segured to ether by the action of said binder substant1ally'gr1ly,at their points of contact. In its finished form the material isfcgllular or porous, the cells or pores, which "fifia'air spaces, being formed by the irregular engagement of the coated granules with each other and extending throughout the entire material and up to and penetrating the exposed surface or surfaces thereof. The air spaces, cells or pores are of irregular form and generally speaking communicate with each other so that in practice the material may be said to have a sponge-like appearance. These air spaces, cells or pores are so related to each other and of such proportions as to give the finished product the property of absorbing in excess of fifteen per cent. of sounds.

The material may be produced in various ways, the following described methods having been found gatisiactory. If the binder in question is a r in er suc 1 as cement plaster or the like, the granules of cork or other similar material are first m o1stened with water and then mixed with the cement, plaster or the like while the latter is in a dry condition. The mixing may take place in a tub or other suitable receptacle in any suitable proportions but preferably in the ratio of approximately three parts of cork to one part of binder by measure. In the process of mixing the cork granules are practically rolled about in the dry binder while the latter may be said to be tossed about so that each granule of cork or the like becomes covered with a coating of the binder which has absorbed the moisture from said granules and has thus become a wet binder. After being thoroughly mixed it will be found that the granules have picked up substantially all of the binder material and that said granules are in irregular engagement with each other with only limited points of contact so that spaces exist between adjacent granules or groups of granules which openly penetrate or terminate in the surface of the material and ex tend throughout the same. The binder eventually becomes hardened and thus serves to unite or secure the granules together in such irregular, limited contact so that the final result is a material of cellular or porous structure.

If the binder which is used is a fluid binder, such as glue or the like, the granules o cork or the like are not first moistened but may be combined with the binder in dry condition and mixed therewith. In this case the proportions which have been found to produce satisfactory results are three parts of cork to one half of one part of binder, also by measure. Otherwise the procedure may be the same as with a dry binder, the resulting material having the same general structural characteristics.

While still wet or in other words before the binder in either case has set or hardened the material 5 may be spread upon a centerheard-Mgr ing of arch formation, as shown at 6 in Figs. 1 and 2, or it may be spread over an upright wall in the same way as is done with a plaster. When used to form the exposed surface of an arch, a supporting backing for carrying the material is preferably provided, which backing may comprise a mass 7 of concrete, mortar, plaster or the like as shown in Fig. 1, or one or more courses 8 of rough tile or the like as shown in Fig. 2, the tiles in the latter case being joined together by mortar, cement, plaster or other preferably elastic binder 9. In either case after the concrete or the like 7 in Fig. l or the binder 9 in Fig. 2 has set, the material 5 in its final condition will be firmly and securely supported in the form of an arch. The said material is further capable of being cast in the form of tiles, slabs, bricks or the like, as shown in Fig. 3, which may be utilized in the construction of walls, ceilings and the like and said material may also be given the form of a molding as shown in Fig. 4. Vhen used in the form of tiles etc. it is preferable to combine the material 5 with a backing 7 a which may consist of concrete, or the like or of any other material which will rigidly support said material. In the same way the molding 5", formed of the material, is also preferably combined with a suitable backing 7". If the backing in any case is of a coalescent material, the material and backing are preferably combined while both are in a wet state so that an extremely intimate bond between the two is secured. The backing of whatever form it may be serves to take up strains and thus relieves the material itself from excessive stress tending to fracture or injure same. It will of course be understood that in some cases the backing may be omitted.

If, after the material is spread over a surface and has become set and the centering has been removed, said finished material is found to be weak, additional glue or other binder may be spread over the exposed surface of the material, by brushing or otherwise, and then forced into the cells, pores or air spaces in any suitable manner, as by air pressure. This causes this additional binder to be added to the initial coating of the granules and thus increases the holding effect and more firmly binds the said granules together without materially diminishing the dimensions of the air spaces, cells or pores. By regulating the pressure, the additional binder may be forced into the material to any desired-extend and at the end of the operation may have substantially disappeared from the exposed surface of said material. The binder, if desired, may be colored in imitation of any substance and as the finished material presents substantially only the binder to view, owing to the fact that the granules are coated therewith, it will readily be apparent that any variety of effects may be had in said material without affecting its utility. Different types of stones may also be imitated by using cork or other material in granular forms of different coarseness.

My improved material is extremely light in weight, is easily produced in finished form or applied to a surface, and may be used to form the exposed surface of walls or ceilings of rooms, auditoriums and the like, as will be readily apparent. The said material, owing to its structure, will absorb sound in excess of fifteen per cent. and will prevent excessive reverberation and echoes and undesirable focusing of sound, so that the acoustics of a room, auditorium, chamber or the like will be materially improved, and certain types of acoustical difficulties will be absolutely overcome. My improved material, when in place, also presents an attractive appearance. It will, of course, be understood that the mixing proportions as well as other details mentioned herein may be changed and varied to meet the requirements of any particular case and further that other changes may be made within the scope of the claims without departing from the spirit of my invention.

It will further be understood that the coated granules are not subjected to any special pressure to unite same but that the material is formed by permitting said granules to become connected with each other by the action of the binding substance substantially only at their points of contact. In this way the air spaces between the granules are preserved and the material having the desired properties or characteristics is produced.

I claim:

1. A sound-absorbent material for walls, floors and ceilings consisting of particles of body material and a binding substance bonding said particles to each other only at their points of contact so as to form a cellular ma terial.

2. A sound-absorbent material adapted to be secured to and form the exposed finished face of walls, floors and ceilings, consisting of particles of body material and a binding substance bonding said particles to each other only at their points of contact so as to form a cellular material.

3. A sound-absorbent material for walls, floors and ceilings consisting of particles of body material bonded to each other only at their points of contact, the size of the particles being such that when so bonded together the interstices between the particles possess the property of absorbing in excess of fifteen per cent. of sounds.

4. A sound-absorbent material for walls, floors and ceilings consisting of particles of body material bonded to each other at limited points of contact thereby providing pores which intercommunicate and openly penetrate the exposed surface and which possess the property of absorbing in excess of fifteen per cent. of sounds.

5. A sound-absorbent material for walls, floors and ceilings consisting of particles of cork and a binding substance bonding said particles of cork to each other only at their points of contact so as to form a cellular material.

6. The method of producing a sound absorbing material of the kind described which consists in providing particles of material with a coating of binding substance and bonding said coated particles to each other at their points of contact only in the form of a cellular sound absorbent material.

7. The method of producing a sound absorbing material of the kind described which consists in taking particles of material, moistening said particles and then mixing said moistened particles with a. dry binder and bonding them to each other at their points of contact only in the form of a sound absorbent material.

8. In the method of producing a sound ab sorbing material of the kind described the steps which consists in taking particles of cork, moistening said particles and then mixing said moistened particles with a dry binder.

In testimony whereof, I have hereunto set my hand.

JOHN COMERMA.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

